Merge branch 'cc/replace-graft-peel-tags'

When given a tag that points at a commit-ish, "git replace --graft"
failed to peel the tag before writing a replace ref, which did not
make sense because the old graft mechanism the feature wants to
mimick only allowed to replace one commit object with another.
This has been fixed.

* cc/replace-graft-peel-tags:
replace: peel tag when passing a tag first to --graft
replace: peel tag when passing a tag as parent to --graft
t6050: redirect expected error output to a file
t6050: use test_line_count instead of wc -l

diff --combined builtin/replace.c
index f5701629a8a5698a64c91ca92226e6da72697441,a06dc2b5015cd064c3044969508f9bffb193872c..644b21ca8d57a75fa83ecbf0e58dd07a685cd9e4
--- 1/builtin/replace.c
--- 2/builtin/replace.c
+++ b/builtin/replace.c
@@@ -82,10 -82,6 +82,10 @@@ static int list_replace_refs(const cha
                data.format = REPLACE_FORMAT_MEDIUM;
        else if (!strcmp(format, "long"))
                data.format = REPLACE_FORMAT_LONG;
 +      /*
 +       * Please update _git_replace() in git-completion.bash when
 +       * you add new format
 +       */
        else
                return error(_("invalid replace format '%s'\n"
                               "valid formats are 'short', 'medium' and 'long'"),
@@@ -370,16 -366,19 +370,19 @@@ static int replace_parents(struct strbu
        /* prepare new parents */
        for (i = 0; i < argc; i++) {
                struct object_id oid;
+               struct commit *commit;
+ 
                if (get_oid(argv[i], &oid) < 0) {
                        strbuf_release(&new_parents);
                        return error(_("not a valid object name: '%s'"),
                                     argv[i]);
                }
-               if (!lookup_commit_reference(the_repository, &oid)) {
+               commit = lookup_commit_reference(the_repository, &oid);
+               if (!commit) {
                        strbuf_release(&new_parents);
-                       return error(_("could not parse %s"), argv[i]);
+                       return error(_("could not parse %s as a commit"), argv[i]);
                }
-               strbuf_addf(&new_parents, "parent %s\n", oid_to_hex(&oid));
+               strbuf_addf(&new_parents, "parent %s\n", oid_to_hex(&commit->object.oid));
        }
  
        /* replace existing parents with new ones */
@@@ -478,15 -477,18 +481,18 @@@ static int create_graft(int argc, cons
  
        strbuf_release(&buf);
  
-       if (oideq(&old_oid, &new_oid)) {
+       if (oideq(&commit->object.oid, &new_oid)) {
                if (gentle) {
-                       warning(_("graft for '%s' unnecessary"), oid_to_hex(&old_oid));
+                       warning(_("graft for '%s' unnecessary"),
+                               oid_to_hex(&commit->object.oid));
                        return 0;
                }
-               return error(_("new commit is the same as the old one: '%s'"), oid_to_hex(&old_oid));
+               return error(_("new commit is the same as the old one: '%s'"),
+                            oid_to_hex(&commit->object.oid));
        }
  
-       return replace_object_oid(old_ref, &old_oid, "replacement", &new_oid, force);
+       return replace_object_oid(old_ref, &commit->object.oid,
+                                 "replacement", &new_oid, force);
  }
  
  static int convert_graft_file(int force)